Impact of storage on sterility of surgical instruments in autoclave bags

Background: There is no published veterinary research to support an optimal storage duration and method of sterile surgical instrumentation (SI) when using self-seal autoclave bags (SSABs), although aspects of research from human healthcare are transferable. Multiple pieces of research in human healthcare have demonstrated the ability of sterilisation packaging materials to maintain barrier integrity and sterility for several months poststerilisation. Research on an optimal storage method is inconclusive. Aims: To determine an ideal storage duration and method of single SI, packaged in SSABs and sterilised via an autoclave. To determine the current practice of sterilisation, storage methods and durations using SSABs in small animal practice. Methods: This mixed methods study consisted of an online questionnaire to investigate the current procedures for autoclave sterilisation in veterinary practice. Alongside this, a non-randomised control study was conducted to assess the sterility of single SI, packaged in SSABs and sterilised via autoclave, to determine an ideal storage duration and method. SI was sterilised and stored for one, three and six months, in open (on a shelf) and closed (in a box) environments. Results: The questionnaire indicated veterinary professionals are adopting a cautious approach to storage durations with 75.5% (n=40) storing sterile single SI for between one and three months, prior to reprocessing. The experimental study did not identify an optimal storage method and either open or closed could be used for effective storage in undisturbed conditions. It is highly probable that most SI were sterile at the end of the storage durations and for up to 6 months. Conclusions: Laboratory findings are mostly consistent with those in existing literature. Results suggest the storage of sterile SI, in either open or closed environments for up to 6 months was not detrimental to the sterility of the instruments. To encourage good sustainability performance, practices could extend the storage times of sterilised SI prior to reprocessing.